A variety of communications protocols and systems may use frequency division duplex (FDD) mechanism for wireless communications, particularly mobile communications. In FDD, the transmission of data from the user device (i.e., uplink) uses a different frequency band or channel than the receipt of data by the user device (i.e., downlink). The user device may have a single antenna and associated transceiver for the purposes of both receiving data via the receive (Rx) channel and transmitting data via the transmit (Tx) channel. The antenna, in this case, may be tuned such that its resonant frequency is at a frequency between the frequency band of the Rx channel and the Tx channel.